Biology 1010 Exam 3 Complete Study Guide –
100+ Actual Exam Questions with Correct
Answers, Detailed Explanations & Rationales
(Graded A+) – 2026
Exam Overview
Biology 1010 Exam 3 typically covers evolution, speciation, population genetics, the history
of life, and prokaryotic diversity . This question bank covers these core topics with verified
answers and rationales from multiple exam review sources .
SECTION 1: EVOLUTION & NATURAL SELECTION (Questions 1-15)
Q1. Place these levels of classification in order from least inclusive to most inclusive:
class, domain, family, genus, kingdom, order, phylum, species
Answer: species, genus, family, order, class, phylum, kingdom, domain
Rationale: The taxonomic hierarchy from most specific (least inclusive) to most broad (most
inclusive) is: Species → Genus → Family → Order → Class → Phylum → Kingdom →
Domain. This classification system was developed by Linnaeus and reflects increasing
levels of biological relatedness .
Q2. Which of the following is a true statement about Charles Darwin?
Answer: He proposed natural selection as the mechanism of evolution
Rationale: Darwin's major contribution was proposing natural selection as the mechanism
driving evolutionary change. He was not the first to propose that species change over time,
nor did he base his theory on inheritance of acquired traits (that was Lamarck). His theory
was built on observations from the Galapagos Islands and his reading of Thomas Malthus
on population growth .
Q3. How did the insights of Lyell and other geologists influence Darwin's thinking
about evolution?
,Answer: Lyell and other geologists presented evidence for the gradual change of geologic
features over millions of years. Darwin applied this idea to suggest that species evolve
through the slow accumulation of small changes over long periods of time.
Rationale: Lyell's Principles of Geology argued that Earth's features formed through
gradual processes over vast timescales. This provided Darwin with the conceptual
framework that evolution is gradual rather than sudden, and that Earth is old enough for
natural selection to have produced the diversity of life .
Q4. Define fitness from an evolutionary perspective
Answer: The fitness of an individual (or of a particular genotype) is measured by the
relative number of alleles that it contributes to the gene pool of the next generation
compared with the contribution of others. Thus, the number of fertile offspring produced
determines an individual's fitness.
Rationale: Evolutionary fitness is about reproductive success—not strength, speed, or
survival alone. An organism that lives a long time but produces no offspring has zero
fitness. Fitness is always relative to other individuals in the population .
Q5. Which process is the ultimate source of the genetic variation that serves as raw
material for evolution?
Answer: Mutation
Rationale: While sexual reproduction shuffles existing alleles and creates new
combinations, only mutation creates entirely new alleles. Mutations are the ultimate source
of all genetic variation in populations. Without mutation, evolution would eventually stop
because there would be no new genetic material for natural selection to act upon .
Q6. As a mechanism of evolution, natural selection can be most closely equated with
what?
Answer: Unequal reproductive success
Rationale: Natural selection occurs when individuals with certain traits produce more
surviving offspring than others. This "unequal reproductive success" is the engine of natural
, selection. Some individuals contribute more alleles to the next generation than others due to
their heritable traits .
Q7. Compare and contrast how the bottleneck effect and the founder effect can lead
to genetic drift
Answer: Both effects result in populations small enough for significant sampling error in the
gene pool for the first few generations. A bottleneck event reduces the size of an existing
population in a given location. The founder effect occurs when a new, small population
colonizes a new territory.
Rationale: Both are forms of genetic drift—random changes in allele frequencies due to
chance events. In a bottleneck (e.g., natural disaster, hunting), the surviving population may
have allele frequencies that differ from the original population. In founder effect, a small
group colonizes a new area, carrying only a subset of the original population's genetic
diversity .
Q8. In a particular bird species, individuals with average-sized wings are more likely
to survive severe storms than other birds in the same population with longer or
shorter wings. This is an example of:
Answer: Stabilizing selection
Rationale: Stabilizing selection favors intermediate phenotypes and reduces variation in a
trait. Both extremes (long and short wings) are selected against, while the average trait is
favored. This type of selection reduces phenotypic diversity while maintaining the status
quo .
Q9. A change in the frequency of an allele in a population over time is called:
Answer: Microevolution
Rationale: Microevolution is defined as a change in allele frequencies within a population
over generations. This is the smallest scale of evolutionary change and is the population-
level process that can eventually lead to speciation and macroevolution .
100+ Actual Exam Questions with Correct
Answers, Detailed Explanations & Rationales
(Graded A+) – 2026
Exam Overview
Biology 1010 Exam 3 typically covers evolution, speciation, population genetics, the history
of life, and prokaryotic diversity . This question bank covers these core topics with verified
answers and rationales from multiple exam review sources .
SECTION 1: EVOLUTION & NATURAL SELECTION (Questions 1-15)
Q1. Place these levels of classification in order from least inclusive to most inclusive:
class, domain, family, genus, kingdom, order, phylum, species
Answer: species, genus, family, order, class, phylum, kingdom, domain
Rationale: The taxonomic hierarchy from most specific (least inclusive) to most broad (most
inclusive) is: Species → Genus → Family → Order → Class → Phylum → Kingdom →
Domain. This classification system was developed by Linnaeus and reflects increasing
levels of biological relatedness .
Q2. Which of the following is a true statement about Charles Darwin?
Answer: He proposed natural selection as the mechanism of evolution
Rationale: Darwin's major contribution was proposing natural selection as the mechanism
driving evolutionary change. He was not the first to propose that species change over time,
nor did he base his theory on inheritance of acquired traits (that was Lamarck). His theory
was built on observations from the Galapagos Islands and his reading of Thomas Malthus
on population growth .
Q3. How did the insights of Lyell and other geologists influence Darwin's thinking
about evolution?
,Answer: Lyell and other geologists presented evidence for the gradual change of geologic
features over millions of years. Darwin applied this idea to suggest that species evolve
through the slow accumulation of small changes over long periods of time.
Rationale: Lyell's Principles of Geology argued that Earth's features formed through
gradual processes over vast timescales. This provided Darwin with the conceptual
framework that evolution is gradual rather than sudden, and that Earth is old enough for
natural selection to have produced the diversity of life .
Q4. Define fitness from an evolutionary perspective
Answer: The fitness of an individual (or of a particular genotype) is measured by the
relative number of alleles that it contributes to the gene pool of the next generation
compared with the contribution of others. Thus, the number of fertile offspring produced
determines an individual's fitness.
Rationale: Evolutionary fitness is about reproductive success—not strength, speed, or
survival alone. An organism that lives a long time but produces no offspring has zero
fitness. Fitness is always relative to other individuals in the population .
Q5. Which process is the ultimate source of the genetic variation that serves as raw
material for evolution?
Answer: Mutation
Rationale: While sexual reproduction shuffles existing alleles and creates new
combinations, only mutation creates entirely new alleles. Mutations are the ultimate source
of all genetic variation in populations. Without mutation, evolution would eventually stop
because there would be no new genetic material for natural selection to act upon .
Q6. As a mechanism of evolution, natural selection can be most closely equated with
what?
Answer: Unequal reproductive success
Rationale: Natural selection occurs when individuals with certain traits produce more
surviving offspring than others. This "unequal reproductive success" is the engine of natural
, selection. Some individuals contribute more alleles to the next generation than others due to
their heritable traits .
Q7. Compare and contrast how the bottleneck effect and the founder effect can lead
to genetic drift
Answer: Both effects result in populations small enough for significant sampling error in the
gene pool for the first few generations. A bottleneck event reduces the size of an existing
population in a given location. The founder effect occurs when a new, small population
colonizes a new territory.
Rationale: Both are forms of genetic drift—random changes in allele frequencies due to
chance events. In a bottleneck (e.g., natural disaster, hunting), the surviving population may
have allele frequencies that differ from the original population. In founder effect, a small
group colonizes a new area, carrying only a subset of the original population's genetic
diversity .
Q8. In a particular bird species, individuals with average-sized wings are more likely
to survive severe storms than other birds in the same population with longer or
shorter wings. This is an example of:
Answer: Stabilizing selection
Rationale: Stabilizing selection favors intermediate phenotypes and reduces variation in a
trait. Both extremes (long and short wings) are selected against, while the average trait is
favored. This type of selection reduces phenotypic diversity while maintaining the status
quo .
Q9. A change in the frequency of an allele in a population over time is called:
Answer: Microevolution
Rationale: Microevolution is defined as a change in allele frequencies within a population
over generations. This is the smallest scale of evolutionary change and is the population-
level process that can eventually lead to speciation and macroevolution .
